Sharpening device suitable for gramophone needles



SHARPENING DEVICE SUITABLE FOR G-RAMOPHONE NEEDLES Filed Jan. 12, 1940 Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE SHARPENIN G DEVICE SUITABLE FOR GRAMOPHONE NEEDLES Alfred Godfrey Imhof, London, England Application January 12, 1940, Serial No. 313,645 In Great Britain January 6, 1939 4 Claims.

- article to be sharpened,.is mounted in a holder which is caused to revolve while in contact with an abrasive surface.

The sharpening device according to this invention comprises a base: or support having a carrier on which is revolvably mounted the needle or like holder, the holder being so arranged that on movement of the carrier, the holder or a wheel thereon will bear with sufficient pressure against the support to cause it to revolve so that the needle can be sharpened against a strip of abrasive material onthe base.

In one way of carrying out the invention, the base may comprise a plate, having a rail on which the carrier, in the form of a sleeve, is freely mounted so that when the needle holder and thus the needle is moved up and down the rail, it can be brought to bear, while driving, with sufficient pressure on the abrasive strip to point the needle.

The needle holder may consist of a spindle on which is fast a wheel and having at its end a chuck device, which may be screw or spring actuated, to receive the needle.

The invention is illustrated in the accompanying drawing which is a perspective view of a sharpening device constructed in accordance with a preferred embodiment of the invention.

Referring to the drawing, the sharpening device comprises a base A the under side of which is conveniently flat so that if necessary it can be screwed down to a gramophone top or a convenient shelf and for which purpose it is provided with screw holes B.

Slidable on the base is a carrier C, on which is revolvably mounted a chuck D constituting the needle holder, the holder, by moving the carrier C to and fro, being caused to revolve so as to sharpen the needle which is pressed against an abrasive surface.

On the base A, which conveniently may be formed of a plastic moulding, is provided a rail E. The rail E extends the length of the base, being fixed in upstanding end walls F and slidable along the rail E is the carrier C, which, in addition, is free to rock thereon so that the angular position of the needle holder may be varied with the object of controlling the pressure between the holder and the abrasive surface, indicated at G, against which the needle is rubbed. The abrasive surface may be formed by a cardboard strip provided with a sanded facing and which is removably held beneath upturned ears H on the base.

Journalled on the carrier C is a spindle J on the end of which is the needle holder D and integral with the spindle is a friction wheel K, which preferably is fitted, as shown with a rubber tyre L. The tyre L, when the device is in use, is pressed lightly against a track portion M formed on the base which may be constituted by a roughened surface to prevent slipping.

As shown, the spindle J may bemounted on a stub projecting from one side ofthe carrier C and from the side projects a finger piece or handle to facilitate operation of the device.

In operation, when it is desired to sharpen the needle, the latter is first inserted in the chuck or holder D which may be screw or spring, actuated, when, by transversing the carrier C up and down its-rail and by applying a slight leverage on the finger 0 the wheel K is pressed against the track M, so causing it to revolve.

The parts are so dimensioned and angled that, when the wheel K is in its driving position, the point of the needle will be brought to bear on the abrasive surfaceG with sufficient pressure to sharpen it, thus giving a simple means of controlling the pressure on the needle.

In the particular embodiment illustrated the needle holder during sharpening rests at an angle to the base of the support, but obviously by setting the strip G at a suitable angle to the support so that it faces towards the needle point, the needle holder will take up a horizontal position and move in a plane parallel to that of the support.

What I claim is:

1. A base, abrasive means on said base, a guide bar on said base, a carriage comprising a sleeve embracing said guide bar and slidable and angularly movable thereon, about the longitudinal axis of the guide bar, the sleeve embracing the guide bar so snugly as to prevent any appreciable other relative movement of the sleeve and guide bar, a chuck device rotatably supported by said carriage, and extending from said guide bar towards said abrasive means, said chuck device being adapted to receive and positively clamp without. permitting lateral play a needle to be sharpened on said abrasive means, a deformable friction wheel connected to said chuck, a track portion having a roughened surface on said base engaged by said friction wheel, and a handle portion projecting from said carriage and providing a lever arm by which said carriage can be slidden and angularly rocked on said guide.

2. A base, abrasive means detachably mounted on said base, a guide bar on said base, a carriage comprising a sleeve embracing said guide bar and slidable and angularly movable thereon, about the longitudinal axis of the guide bar, the sleeve embracing the guide bar so snugly as to prevent any appreciable other relative movement of the sleeve and guide bar, a chuck device rotatably supported by said carriage, and extending from said guide bar towards said abrasive means, said chuck device being adapted to receive and positively clamp without permitting lateral play a needle to be sharpened on said abrasive means, a deformable friction wheel connected to said chuck, a track portion having a roughened surand a handle portion projecting from said carriage and providing a lever arm by which said carriage can be slidden and angularly rocked on said guide.

3. A base, lugs on said base, abrasive means detachably secured by said lugs on said base, a guide bar on said base, a carriage comprising a sleeve embracing. said guide bar and slidable and angularly movable thereon, about the longitudinal axis of the guide bar, the sleeve embracing the guide bar so snugly as to prevent any appreciable other relative movement of the sleeve and guide bar, a chuck device rotatably supported by said carriage, and extending from said guide bar towards said abrasive means, said chuck device being adapted to receive and positively clamp without permitting lateral play a needle to be sharpened on said abrasive means, a deformable friction wheel connected to said chuck, a track portion having a roughened surface on said base engaged by said friction wheel, and a handle portion projecting from said carriage and providing a lever arm by which said carriage can be slidden and angularly rocked on said guide.

4. A base member formed of moulded material and having a roughened track surface between two longitudinal edges and upstanding walls at each end and ears adjacent one longitudinal edge, a guide rail supported in said walls to extend adjacent the other long edge, a carriage comprising a sleeve slidable and angularly movable on said rail about the longitudinal axis of the rail, the sleeve embracing the rail so snugly as to prevent any appreciable other relative movement of the sleeve and rail, a chuck rotatably carried by said carriage, said chuck device being adapted to receive and positively clamp without permitting lateral play a needle to be sharpened on said abrasive means, a resilient driving 

